The present invention relates to a waveguide switching device comprising: a body with four ports located on four mutually perpendicular sides thereof. A rotor member mounted in this body and provided with two circle arc symmetrical channels having an opening which is substantially 90.degree. and a cross section substantially coinciding with the cross-section of the ports and driving means for bringing the rotor member to two switching positions so the channels selectively connect with the ports.
As is known, waveguide switches are provided with a substantially cube-shaped metal body including on four mutually perpendicular faces, a rectangular shape port, a waveguide being coupled to each of the ports. At the central portion of the body there is mounted a substantially cylindrical rotor provided with two 90.degree. circle arc symmetrical channels having a like cross section to that of the ports. These switches further comprise driving means causing the rotor to connect said ports in different ways, in pairs, through said channels; in other words at a switching position the waveguides are coupled in pairs according to a given way through the rotor channels whereas at the other switching position said ports are coupled differently.
An ideal switch of the above mentioned type would have a zero switching time as well zero losses. Moreover it would be provided with an infinite insulation and driving means as small as possible.
On the other hand, presently known switches have comparatively long switching times, high losses and large size which negatively affects their use in aircraft applications. In general prior art switches have switching times on the order of 1/10 sec.; insertion losses which, instead of being zero, amount to several hundred dB; a standing wave ratio of the order of 1.05 (whereas an ideal ratio would be 1) and an isolation of the order of 60 dB (whereas it should be infinite).
Moreover the overall size, which would ideally coincide with that of the metal cube, is much larger than the metal cube size, frequently over two times as large, because of the volume required by the electric motors provided for driving and braking the rotor.
The long switching time and large size are such greatly limit, in actual practice, the use of mechanical switching device. In fact, as a high switching speed an/or small size are required, solid state switches are used which, while they operate with very high speeds, have losses much greater than those of the mechanical switches.